With the popularity of a wide variety of appliances (such as household electrical appliances), when using the appliances, users pay increasingly more attention to the safety performance of the appliances. In related arts, a fan, for example, is usually disposed in an appliance, such as a refrigerator, an air conditioner, a humidifier, or an air purifier. Sometimes, these appliances become abnormal while being used, but a user may not necessarily find the abnormality in time. For example, in some instances, a fan will run with an abnormality which can cause damage to the appliance or its surroundings. Also, there are certain potential safety hazards associated with such abnormalities. Currently, abnormal operations in appliances may be discovered and then turned off manually. In some instances, there are automated shutdown functions. Described herein are example technical solutions to the technical problems that may occur from abnormalities in operation of appliances.